Nickel(II) hydride and fluoride pincer complexes and their reactivity with Lewis acids BX3 center dot L ( X = H, L = thf; X = F, L = Et2O)

Reaction of the pincer hydride complex ((PCP)-P-tBu)Ni(H) [(PCP)-P-tBu = 2,6-C6H3((CH2PBu2)-Bu-t)(2)] with BH3 center dot thf in THF at 190 K generates the corresponding borohydride complex ((PCP)-P-tBu)Ni(BH4). The kinetically stable (but thermodynamically unstable) species undergoes reversible borane loss. The related fluoride complex ((PCP)-P-tBu)Ni(F) shows the same reactivity towards BF3 center dot Et2O, producing ((PCP)-P-tBu)Ni(BF4) as the main final product. The processes were followed through multinuclear NMR spectroscopy and DFT calculations, at the M06//6-31+ G(d,p) level of theory.